This invention relates to a functional material using volatile agents such as fragrant agents, deodorant agents, antibacterial agents, antifungal agents and/or mothproofing agents, and containing a dye that permits visual checking of the end of volatilization of the volatile agent.
There is known a material containing a volatile agent such as a fragrant agent and a volatile dye so that the residual amount of the agent and thus its effects are visually checkable based on the degree of fading of the color.
But in such a material, the volatile agent and the dye do not necessarily volatilize at the same rate. Thus, if the dye volatilizes completely before does the volatile agent, a user may judge that the volatile agent has also gone completely and discard the material in spite of the fact that there still remains a considerable amount of volatile agent. Conversely, the volatile agent may volatilize completely before does the dye. In such a case, a user will keep using the material in spite of the fact that it has no effects any more.
There is also known a material containing a volatile agent and an organic color compound so that the effects of the agent are visually checkable based on the change in color of the compound resulting from its chemical change with the volatilization of the volatile agent. In this case, although there is no problem of time difference between the expiration of effects of the agent and the color change, the combination of a volatile agent and an organic color compound poses a big problem. In other words, the kind of volatile agents usable in combination with a particular organic color compound is very limited. Also, even if the combination is possible, most organic color compounds tend to deepen in color with volatilization of the agent. Deep color tends to give a wrong impression to a user that the material is brand-new and contains an ample amount of volatile agent even when actually the agent has run out.
An object of the present invention is to provide a functional material that makes it possible to visually check the end of volatilization of a volatile agent from the degree of fading of the color, and to use practically any kind of volatile agents in which an oil-soluble dye is dissolvable.